The present invention relates to absorbent articles, and more particularly to absorbent articles having active graphics that can change color during use.
The toilet training process may incorporate a wide variety of different aspects, including many training techniques and training aids that may be used by parents and caregivers, hereinafter simply referred to as caregivers. One aspect of the total toilet training process is the change from diapers to training pants to help the child understand that he or she should now use the toilet just like adults. Another aspect of the total toilet training process includes caregiver instruction as a positive encouragement and reinforcement to the child that he or she should now be using a toilet instead of diapers. Although the use of training pants and positive encouragement from the caregiver has been helpful in the toilet training process, there is still much room for improvement. Specifically, caregivers are still searching for easier and quicker ways to guide their children successfully through the toilet training process.
Many caregivers have difficulty in determining the readiness of a child to begin the toilet training process, and underestimate the difficulty of teaching the toilet training process to young children. If a child does not respond to an initial toilet training instruction or introduction, the caregiver can be at a loss for finding techniques, methods, or teaching tools to encourage the child to master the art of toilet training. Thus, while various teaching tools such as books, videotapes, charts with stickers, personalized toilets, and interactive toilet training kits are available, there remains a need for new and improved educational and motivational mechanisms to facilitate the toilet training process.
In response to the discussed deficiencies associated with prior absorbent garments, an absorbent article has been developed that provides toilet training aid benefits through the use of interactive graphics, which can include one or more active graphics. Certain graphics are referred to as xe2x80x9cactivexe2x80x9d because they are constructed to xe2x80x9cdisappearxe2x80x9d or xe2x80x9cappearxe2x80x9d from view, such as when the child has an accident and the active graphic is contacted with urine or upon prolonged exposure to the environment. The interactive wetness indicating graphics can also include one or more permanent graphics which can, in combination with the active graphics, provide a story line that is useful to teach the child important lessons regarding toilet training.
Hence, in one embodiment, the invention concerns an absorbent article that includes an outer cover having in interior surface and an opposite exterior surface, where the outer cover has a first color. The absorbent article also includes an absorbent assembly disposed on the interior surface of the outer cover. An active graphic of the absorbent article is disposed on the outer cover and comprises a color change composition. The active graphic has a pre-activation color different from the first color and a post-activation color substantially the same as the first color. As used herein, the phrase xe2x80x9cpost-activation color substantially the samexe2x80x9d as another color includes the same color, visually similar colors and clear.
In another embodiment, the absorbent article can also include a background graphic disposed on the outer cover and having a second color different from the outer cover first color. The active graphic can have a pre-activation color different from the first color and the second color and a post-activation color substantially the same as the second color.
In a further embodiment, the active graphic can comprise at least two color change compositions that have a pre-activation color different from the outer cover first color and the background graphic second color. At least one of the color change compositions can have a post-activation color substantially the same as the first color, and at least one of the color change compositions can have a post-activation color substantially the same as the second color.
In yet another embodiment, the active graphic can comprise a first active graphic and a second active graphic that are disposed on the outer cover and that comprise color change compositions. The first active graphic can have a pre-activation color different from the outer cover first color and the background graphic second color and a post-activation color substantially the same as the second color. The second active graphic can have a pre-activation color substantially the same as the first color and a post-activation color substantially the same as the second color.
In another embodiment, the invention concerns an absorbent article that includes an outer cover having an interior surface, an opposite exterior surface and a first color. An absorbent assembly is disposed on the interior surface of the outer cover. An active graphic of the absorbent article is disposed on the outer cover and comprises a color change composition providing a pre-activation color substantially the same as the first color and a post-activation color different from the first color. This embodiment provides an active graphic that appears over time.
The term xe2x80x9cactive graphicxe2x80x9d as used herein refers to an appearing graphic, a fading graphic, or a combination of appearing and fading graphics. The term xe2x80x9cappearing graphicxe2x80x9d is used herein to refer to a graphic that becomes visible or becomes significantly more visible when exposed to urine, or that becomes visible or becomes significantly more visible with the passage of time when exposed to the environment but not exposed to urine. Conversely, the term xe2x80x9cfading graphicxe2x80x9d is used herein to refer to a graphic that becomes invisible or becomes significantly less visible when exposed to urine, or that becomes invisible or becomes significantly less visible with the passage of time when exposed to the environment but not exposed to urine.
In any of the above-referenced and further embodiments of the absorbent article, the active graphics can comprise moisture sensitive color change compositions. The term xe2x80x9cmoisture sensitive color change compositionxe2x80x9d refers to an active graphic that changes color from a pre-activation color to a post-activation color when exposed to liquid such as urine. Suitable compositions can comprise an ink, an adhesive, or the like that changes color when exposed to an aqueous solution such as urine. Such active graphics can comprise a fading graphic or an appearing graphic, whereupon the color change composition can be adapted to blend in with a background or surrounding color, either before or after exposure to the aqueous solution. Suitable compositions of this color-change type are available from a variety of commercial vendors, such as such as a pH-change/color-change hot melt adhesive available from Findley Adhesives, Inc. of Wauwatosa, Wis., USA. Other potentially suitable means by which a color may be made to appear or disappear, or by which one color may be converted or appear to be converted into another, include chemical reactions resulting from interaction with urine or from dissolution of spatially separated reactants into urine. Such reactions may include but are not limited to color changes of pH indicating molecules, formation or degradation of colored complexes, the action of one or more enzymes that occur naturally in urine on colored molecules or precursors thereof, oxidation and/or reduction reactions, and reactions of two or more components that are spatially separated within a product, at least one of which is soluble in urine, and which upon contact, react to create or destroy a colored region. Further examples of potentially suitable means to achieve color changes include the pre-combination of two colors to form a blended color, after the wetting of which one color component may be solubilized or destroyed to leave only the second color component visible, and molecules that exhibit different color properties in crystalline and dissolved states.
Other active graphics of the absorbent article can comprise a fading graphic which is formed from a composition such as an ink that is soluble in aqueous solutions such as urine. The composition can be positioned in the absorbent article so that it becomes wet and dissolves when the product is insulted with liquid. Once dissolved, the composition washes away from the outer cover and is obscured by the outer cover. As a result, the active graphic seems to disappear from view.
Suitable urine-soluble inks are available from a variety of commercial vendors, such as Sun Chemical Corp. of Philadelphia, Pa., USA under the trade designation AQUA DESTRUCT. Particular urine-soluble compositions are disclosed in U.S. Pat. No. 4,022,211 issued May 10, 1977 to Timmons et al., which is incorporated herein by reference. The ink color can be selected to provide a pleasing appearance and graphic impact, including fading rapidly upon contact with liquid. To facilitate rapid fading, the fading graphics can comprise line drawings having a line width of from about 1 to about 2 millimeters. Thus, the active graphic can comprise pH sensitive inks, fugitive inks, colored absorbent particles, hydratable salts, moisture sensitive films, enzymes, heat sensitive inks and dyes, or the like.
Fading graphics can simply disappear from view, relative to the exterior surface of the outer cover. For example, fading object graphics can be made to disappear into a permanent background graphic. Representative examples include an object graphic such as yellow fish disappearing or fading into a background graphic such as blue water or green weeds; an object graphic such as pink flowers fading into a background graphic such as a green lawn; an object graphic such as lavender sand toys fading into a background graphic such as tan sand; an object graphic such as pink sea shells fading into a background graphic such as tan sand; an object graphic such as small animals fading into a background graphic such as a jungle scene; an object graphic such as frogs fading into a background graphic such as water lilies; an object graphic such as green toys fading into a background graphic such as a yellow floor or blanket area; an object graphic such as pink angels fading into a background graphic such as blue clouds; an object graphic such as a red bone fading into a background graphic such as the inside of a dog""s dish; an object graphic such as a cat""s yellow yarn balls fading into a background graphic such as a green checkered floor; an object graphic such as a toy car disappearing from a background graphic such as a road; or the like.
The active graphic can also be configured to appear over time due to exposure to the environment. In particular, the active graphic can be responsive to time intervals, temperature levels, oxygen levels, or the like, and combinations thereof. Various visual indicators that appear over time in response to particular conditions are disclosed in U.S. Pat. No. 5,058,088 issued Oct. 15, 1991 to Haas et al.; U.S. Pat. No. 5,053,339 issued Oct. 1, 1991 to Patel; U.S. Pat. No. 5,045,283 issued Sep. 3, 1991 to Patel; U.S. Pat. No. 4,987,849 issued Jan. 29, 1991 to Sherman; U.S. Pat. No. 4,903,254 issued Feb. 20, 1990 to Haas; U.S. Pat. No. 4,812,053 issued Mar. 14, 1989 to Bhattacharjee; and U.S. Pat. No. 4,292,916 issued Oct. 6, 1981 to Bradley et al.; all of which are incorporated herein by reference. An active graphic that appears over time can be applied to the product when use is initiated, activated when use is initiated such as by removal of a protective cover layer, formed as an integral component of the product, or the like.
In contrast to active graphics, the term xe2x80x9cpermanent graphicxe2x80x9d is used herein to refer to a graphic that does not substantially change its degree of visibility when the absorbent article is insulted with urine and when the absorbent article is exposed to the environment, in simulated use conditions. The change in visibility of a graphic or a portion of a graphic can be determined based on a person""s observation of the graphic before and after the article containing the graphic is exposed to liquid. For purposes hereof, an article is exposed to liquid by immersing the article completely in an aqueous solution containing 0.9 weight percent sodium chloride, used at room temperature (≅23xc2x0 C.), for a period of twenty minutes. After 20 minutes the product is removed from the aqueous solution and placed on a TEFLON(trademark) coated fiberglass screen having 0.25 inch openings, which is commercially available from Taconic Plastics Inc., Petersberg, N.Y., USA, which in turn is placed on a vacuum box and covered with a flexible rubber dam material. A vacuum of 3.5 kilopascals (0.5 pounds per square inch) is drawn in the vacuum box for a period of 5 minutes, after which the article is removed and observed. The person with normal or corrected vision of about 20-20 should make the observations from a distance of 1 meter in an environment providing 30 footcandles (320 Lux) of illumination. Changes in the visibility of the graphic should be identified, and distinguished where necessary from changes in the color of other materials such as fluff pulp within an absorbent assembly. Desirably, the permanent graphic can be configured so that the entire graphic also does not substantially change its appearance, size or shape when the product is insulted with liquid or exposed to the environment.
The graphics of the absorbent article can include object graphics, including but not limited to character graphics, inanimate objects, background graphics, or the like. The term xe2x80x9ccharacter graphicxe2x80x9d is used herein to refer to a graphic containing an anthropomorphous image, and in particular an image having or suggesting human form or appearance which ascribes human motivations, characteristics or behavior to inanimate objects, animals, natural phenomena, cartoon characters, or the like. Ideally the character graphic would be suitable for children""s underwear and could be utilized to motivate children to wear the pants and use a potty or toilet. To that end, the character graphics can be associated with popular characters in the media, advertising or well known in a particular culture. Ideally they are characters that the child or caregiver care about and want to identify with. Ideally the child can imagine himself or herself taking the place of the character. Suitable character graphics can include animals, people, inanimate objects, natural phenomena, cartoon characters, or the like that can or can not be provided with human features such as arms, legs, facial features or the like. The character graphics can comprise permanent graphics, active graphics, or both permanent and active graphics.
The term xe2x80x9cbackground graphicxe2x80x9d is used herein to refer to a graphic that is disposed adjacent to, around, near or surrounding one or more active graphics. The background graphics can comprise permanent graphics, active graphics, or both permanent and active graphics, and can comprise one or a plurality of colors. Desirably, the background graphic is related in subject matter to the active graphic.
As used herein, the phrase xe2x80x9crelated in subject matterxe2x80x9d refers to the situation where the subject matter of one graphic is the same as or is linked to the subject matter of another graphic. The subject matter relationship can be between two or more text messages, between two or more pictorial images, or between a combination of one or more text messages and one or more pictorial images. The term xe2x80x9ctext messagexe2x80x9d means a graphic consisting of one or more alphanumeric symbols, and the term xe2x80x9cpictorial imagexe2x80x9d means a graphic consisting of one or more pictures. The terms xe2x80x9ctext imagexe2x80x9d and xe2x80x9cpictorial imagexe2x80x9d are mutually exclusive as used herein. The general term xe2x80x9cgraphicxe2x80x9d is used herein to mean any design, pattern, or the like that is or becomes visible on an absorbent article, and specifically includes text messages that consist of one or more alphanumeric symbols, pictorial images that consist of one or more pictures, and combinations thereof.
By way of example, two pictorial images are considered related in subject matter where the images are identical; separately illustrate different sizes, shapes, colors of a common object; each illustrate one and the other of two objects that are commonly associated with one another, such as the moon and stars, a body of water and water toys, a sandbox and suitable toys, a baseball bat and ball, a barn and animals, or the like; illustrate different items used in a particular activity, such as a sporting activity, a gardening activity or the like; jointly illustrate geometrically mating or engaging elements such as a triangle and a triangularly-shaped aperture, or two halves of a zipper; each illustrate one part of a multipart picture; or the like. Similarly, two text messages are considered related in subject matter where the messages: are identical; jointly form a sentence, thought, or action such as xe2x80x9cjumpxe2x80x9d and xe2x80x9cupxe2x80x9d; each refer to one and the other of two items that are commonly associated with one another, such as xe2x80x9cbatxe2x80x9d and xe2x80x9cball,xe2x80x9d xe2x80x9cBigxe2x80x9d and xe2x80x9cKid,xe2x80x9d xe2x80x9cBigxe2x80x9d and xe2x80x9cGirl,xe2x80x9d or xe2x80x9cBigxe2x80x9d and xe2x80x9cBoyxe2x80x9d; jointly present a question and answer; or the like. Likewise, a text message and a pictorial image are considered to be related in subject matter where the text names, defines or describes the image; or the like.
In use, the active graphic can appear or fade when an accident occurs and urine comes into contact with the active graphic. Desirably, the active graphic appears or fades in about 3 minutes or less, particularly in about 1 minute or less, and more desirably in about 20 seconds or less, when the absorbent article is insulted with 200 milliliters or more of urine, and more desirably about 40 to about 60 milliliters or more of urine.
The changed condition of the graphic presents a tool for the caregiver to interact with the child and explain why the graphic changed. This is particularly useful at the stage of toilet training where the child is being taught to be aware of going potty and the need to use the bathroom. The combination of active graphics and related permanent graphics are believed to make children more interested in the toilet training process and therefore lead to enhanced results.
Permanent graphics can be positioned anywhere on the outer cover, and in particular embodiments can desirably be positioned in the front waist region along or near the longitudinal centerline of the product. Particular arrangements for permanent and wetness indicating graphics are disclosed in U.S. patent application Ser. No. 09/333,223, filed on Jun. 15, 1999 by Cammarota et al. and titled xe2x80x9cAbsorbent Articles Having Wetness Indicating Graphics Incorporating A Training Zonexe2x80x9d and U.S. patent application Ser. No. 09/333,222, filed on Jun. 15, 1999 by Olson et al. and titled xe2x80x9cAbsorbent Articles Having Wetness Indicating Graphics Providing An Interactive Training Aid.xe2x80x9d
The active graphics can but need not necessarily be positioned closer to the transverse centerline of the product than the permanent graphics. In particular embodiments, the active graphics are positioned between the transverse centerline of the product and the permanent graphic so as to be properly focussed and not hidden from view during use. Locating the active graphics in the crotch region of the product, near the target spot for urination, may also assist with rapid exposure of the fading graphic to urine upon insult. It is desirable to locate active graphics that are moisture sensitive on the area of the outer cover that is most likely to experience wetness during the first void. Of course, alternative positioning of the permanent and active graphics are possible, such as the permanent graphic in the crotch region and the active graphic in one of the waist regions, both permanent and active graphics in one or both of the waist regions and/or the crotch region, or the like. The active graphics can but need not necessarily be positioned on one or more sides of the permanent graphics, such as xe2x80x9cfloatingxe2x80x9d under the permanent graphic. Alternatively, the permanent graphic can surround the active graphic and vice versa.
In one particular embodiment, all of the active object graphics are located in a distinct active graphic region where the child can focus attention. The active graphic region suitably has a length dimension measured parallel to the longitudinal centerline of about 10 centimeters, more particularly about 9 centimeters, and a width dimension measured parallel to the transverse centerline of about 6 centimeters. The active graphic region can, for instance, be spaced from the first end edge of the product by approximately 13 to 16 centimeters.
There can be one or more active object graphics. It is believed desirable to use a plurality of active object graphics in order provide the greatest impact to the child. In particular embodiments, a training pant comprises 3 or more active object graphics, particularly from 4 to 8, such as 5 arranged in a 2-1-2 pattern.
The size of the active object graphics can depend in part on their number and type. It is generally preferred that the active object graphics have a size of at least about 1.5 by 1.5 centimeter and less than about 3 by 3 centimeters, and particularly at least about 1.8 by 1.8 centimeter and less than about 2.5 by 2.5 centimeters.
The overall size of the permanent graphic can be significantly larger than the overall size of each discrete active graphic. In particular embodiments, for instance, the permanent graphic has a size measured by overall surface area that is at least twice as large, and more particularly at least three times as large, as the size of a single active graphic. The maximum length dimension of the permanent graphic, measured parallel to the longitudinal centerline, is desirably about 8 to about 9 centimeters.
The permanent and active graphics are suitably disposed on the outer cover. The term xe2x80x9cdisposed on,xe2x80x9d and variations thereof are intended to mean that one element can be integral with another element, or that one element can be a separate structure bonded to or placed with or placed near another element. Thus, the graphics can be formed or applied directly or indirectly to a surface of the outer cover, formed or applied between layers of a multiple layer outer cover, formed or applied to a substrate that is placed with or near the outer cover, formed or applied within a layer of the outer cover or another substrate, or other variations or combinations thereof. In particular embodiments, the graphics can be printed, sprayed, or otherwise applied directly on a layer of the outer cover. In other embodiments, the graphics can be applied to a layer placed with or near the outer cover, such as a substrate associated with the absorbent assembly, including but not limited to tissue layers, liquid handling layers, absorbent layers, or the like.
The permanent graphics can be located on the exterior surface of the outer cover to enhance the visual impact of the permanent graphics. Alternatively, however, the permanent graphics can be located on the interior surface of the outer cover or between layers of a multilayer outer cover, provided the permanent graphics remain visible from the exterior of the product.
The active graphics can be located on the interior surface of the outer cover, which is particularly desirable for active graphics that are triggered by urine in order to enhance the speed at which the graphics are contacted with urine and thus change their visual appearance. The outer cover desirably comprises a material that is formed or treated to be liquid impermeable. In alternative embodiments, the outer cover can comprise a material that is formed or treated to be at least partially liquid permeable. In this latter case, the active graphics can be located between layers of a multilayer outer cover, or, particularly for appearing graphics, on the exterior surface of the outer cover. Regardless of location, fading graphics should be visible from the exterior of the product before activation and appearing graphics should be visible from the exterior of the product after activation.
xe2x80x9cLiquid impermeablexe2x80x9d, when used in describing a layer or multi-layer laminate, means that a liquid, such as urine, will not pass through the layer or laminate, under ordinary use conditions, in a direction generally perpendicular to the plane of the layer or laminate at the point of liquid contact. Liquid, or urine, can spread or be transported parallel to the plane of the liquid impermeable layer or laminate, but this is not considered to be within the meaning of xe2x80x9cliquid impermeablexe2x80x9d when used herein.
The outer cover can comprise a translucent material that has sufficient opacity, or a transparent or translucent material that is otherwise treated, to mask a urine soluble ink after it has dissolved. Such an outer cover should not be so opaque that the graphics printed on the interior surface of the outer cover or adjacent to the interior surface are obscured. Polymer films used to form the outer cover can be treated with titanium dioxide to make the film appear white and to develop sufficient opacity to mask urine, BM and dissolved inks. Examples of suitable outer cover materials include films formed of polyethylene, polypropylene, cataloy, bi-component, any polymer based extruded film, or the like. One such film is a polyethylene film having a thickness of about 0.2 millimeter (0.75 mil).
The permanent and active graphics can be formed on or applied to the outer cover or another substrate bonded to or placed with or placed near the outer cover by any suitable technique. The graphics are desirably registered with other components of the absorbent article during manufacture such that the graphics are positioned in the desired regions of the product.
For active graphics that are triggered by contact with urine, the active graphic can be in liquid communication with the absorbent assembly of the product. As used herein, the term xe2x80x9cliquid communicationxe2x80x9d means that liquid such as urine is able to travel from one layer or element to another layer or element. The absorbent assembly can but need not include a slot or densified region, incorporate a liquid distribution layer, or the like, to channel or direct liquid to the location near the outer cover where the active graphics are located.
As noted previously, liquid soluble inks can be used to form the active graphics. It is theorized that migration of the dissolved inks away from the outer cover and into the absorbent assembly can improve the fading or disappearing quality of the active graphics. To enhance this effect, the outer cover can be attached to the absorbent assembly in a windowpane design, whereby the active graphic region of the outer cover is not bonded to the absorbent assembly and the regions of the outer cover surrounding the active graphic region are bonded to the absorbent assembly. One suitable method and apparatus for adhesively bonding the outer cover to the absorbent assembly in a windowpane design is disclosed in U.S. Pat. No. 5,683,752 issued Nov. 4, 1997 to Popp et al., which is incorporated herein by reference.
Absorbent articles suitable for use with the present invention include diapers, training pants, incontinence products, diaper pants, disposable underwear, or the like. Suitable training pants and diaper pants can have seamed side portions or refastenable side portions. The present invention is particularly suited for use with training pants or diaper pants to aid in toilet training. One particular training pant suitable for use with the present invention is disclosed in U.S. Pat. No. 4,940,464 issued Jul. 10, 1990 to Van Gompel et al., which is incorporated herein by reference. The Van Gompel et al. patent describes various materials of which the training pant can be made, and a method of constructing a training pant. The training pant can also be constructed using the methods and apparatus disclosed in U.S. Pat. No. 5,766,389 issued Jun. 16, 1998 to Brandon et al., which is also incorporated herein by reference.
The above-mentioned and other features and advantages of the present invention and the manner of attaining them will become more apparent, and the invention itself will be better understood by reference to the drawings and the following description of the drawings.